Ecological classification or ecological typology is the classification of land or water into geographical units that represent variation in one or more ecological features. Traditional approaches focus on geology, topography, biogeography, soils, vegetation, climate conditions, living species, habitats, water resources, and sometimes also anthropic factors. [1] Most approaches pursue the cartographical delineation or regionalisation of distinct areas for mapping and planning. [2]
Different approaches to ecological classifications have been developed in terrestrial, freshwater and marine disciplines. Traditionally these approaches have focused on biotic components (vegetation classification), abiotic components (environmental approaches) or implied ecological and evolutionary processes (biogeographical approaches). Ecosystem classifications are specific kinds of ecological classifications that consider all four elements of the definition of ecosystems: a biotic component, an abiotic complex, the interactions between and within them, and the physical space they occupy (ecotope). [1]
Vegetation is often used to classify terrestrial ecological units. Vegetation classification can be based on vegetation structure and floristic composition. Classifications based entirely on vegetation structure overlap with land cover mapping categories. [3]
Many schemes of vegetation classification are in use by the land, resource and environmental management agencies of different national and state jurisdictions. The International Vegetation Classification (IVC or EcoVeg) has been recently proposed but has not been yet widely adopted. [4]
Vegetation classifications have limited use in aquatic systems, since only a handful of freshwater or marine habitats are dominated by plants (e.g. kelp forests or seagrass meadows). Also, some extreme terrestrial environments, like subterranean or cryogenic ecosystems, are not properly described in vegetation classifications.
The disciplines of phytogeography and biogeography study the geographic distribution of plant communities and faunal communities. Common patterns of distribution of several taxonomic groups are generalised into bioregions, floristic provinces or zoogeographic regions. [5] [6]
Climate classifications are used in terrestrial disciplines due to the major influence of climate on biological life in a region. The most popular classification scheme is probably the Köppen climate classification scheme. [7] Similarly geological and soil properties can affect terrestrial vegetation.
In marine disciplines, the stratification of water layers discriminate types based on the availability of light and nutrient, or changes in biogeochemical properties. [8]
American geographer Robert Bailey defined a hierarchy of ecosystem units ranging from micro-ecosystems (individual homogeneous sites, in the order of 10 square kilometres (4 sq mi) in area), through meso-ecosystems (landscape mosaics, in the order of 1,000 square kilometres (400 sq mi)) to macro-ecosystems (ecoregions, in the order of 100,000 square kilometres (40,000 sq mi)). [9] : Ch:2, p:25–28
Bailey outlined five different methods for identifying ecosystems: gestalt ("a whole that is not derived through considerable of its parts"), in which regions are recognized and boundaries drawn intuitively; a map overlay system where different layers like geology, landforms and soil types are overlain to identify ecosystems; multivariate clustering of site attributes; digital image processing of remotely sensed data grouping areas based on their appearance or other spectral properties; or by a "controlling factors method" where a subset of factors (like soils, climate, vegetation physiognomy or the distribution of plant or animal species) are selected from a large array of possible ones are used to delineate ecosystems. [9] : Ch:3, p:29–40
In contrast with Bailey's methodology, Puerto Rico ecologist Ariel Lugo and coauthors identified ten characteristics of an effective classification system. For example that it be based on georeferenced, quantitative data; that it should minimize subjectivity and explicitly identify criteria and assumptions; that it should be structured around the factors that drive ecosystem processes; that it should reflect the hierarchical nature of ecosystems; that it should be flexible enough to conform to the various scales at which ecosystem management operates. [10]
The International Union for The Conservation of Nature (IUCN) developed a global ecosystem typology that conforms to the definition of ecosystems as ecological units that comprise a biotic component, an abiotic complex, the interactions between and within them, and occupy a finite physical space or ecotope. This typology is based on six design principles: representation of ecological processes, representation of biota, conceptual consistency throughout the biosphere, scalable structure, spatially explicit units, parsimony and utility. This approach has led to a dual representation of ecosystem functionality and composition within a flexible hierarchical structure that can be built from a top-down approach (subdivision of upper units by function) and a bottom-up approach (representation of compositional variation within functional units). [11]
A biome is a distinct geographical region with specific climate, vegetation, and animal life. It consists of a biological community that has formed in response to its physical environment and regional climate. Biomes may span more than one continent. A biome encompasses multiple ecosystems within its boundaries. It can also comprise a variety of habitats.
Ecology is the natural science of the relationships among living organisms, including humans, and their physical environment. Ecology considers organisms at the individual, population, community, ecosystem, and biosphere levels. Ecology overlaps with the closely related sciences of biogeography, evolutionary biology, genetics, ethology, and natural history.
An ecosystem is a system that environments and their organisms form through their interaction. The biotic and abiotic components are linked together through nutrient cycles and energy flows.
An ecoregion is an ecologically and geographically defined area that is smaller than a bioregion, which in turn is smaller than a biogeographic realm. Ecoregions cover relatively large areas of land or water, and contain characteristic, geographically distinct assemblages of natural communities and species. The biodiversity of flora, fauna and ecosystems that characterise an ecoregion tends to be distinct from that of other ecoregions. In theory, biodiversity or conservation ecoregions are relatively large areas of land or water where the probability of encountering different species and communities at any given point remains relatively constant, within an acceptable range of variation . Ecoregions are also known as "ecozones", although that term may also refer to biogeographic realms.
Biogeography is the study of the distribution of species and ecosystems in geographic space and through geological time. Organisms and biological communities often vary in a regular fashion along geographic gradients of latitude, elevation, isolation and habitat area. Phytogeography is the branch of biogeography that studies the distribution of plants. Zoogeography is the branch that studies distribution of animals. Mycogeography is the branch that studies distribution of fungi, such as mushrooms.
Vegetation is an assemblage of plant species and the ground cover they provide. It is a general term, without specific reference to particular taxa, life forms, structure, spatial extent, or any other specific botanical or geographic characteristics. It is broader than the term flora which refers to species composition. Perhaps the closest synonym is plant community, but vegetation can, and often does, refer to a wider range of spatial scales than that term does, including scales as large as the global. Primeval redwood forests, coastal mangrove stands, sphagnum bogs, desert soil crusts, roadside weed patches, wheat fields, cultivated gardens and lawns; all are encompassed by the term vegetation.
A bioregion is a geographical area, on land or at sea, defined not by administrative boundaries but by distinct characteristics such as plant and animal species, ecological systems, soils and landforms, human settlements and cultures those attributes give rise to, and topographic features such as watersheds. The idea of bioregions were adopted and popularized in the mid-1970s by a school of philosophy called Bioregionalism, which includes the concept that human culture, in practice, can influence bioregional definitions. Bioregions are part of a nested series of ecological scales, generally starting with local watersheds, growing into larger river systems, then Level III or IV Ecoregions, bioregions, then biogeographical Realm, followed by the continental-scale and ultimately the biosphere.
Landscape ecology is the science of studying and improving relationships between ecological processes in the environment and particular ecosystems. This is done within a variety of landscape scales, development spatial patterns, and organizational levels of research and policy. Landscape ecology can be described as the science of "landscape diversity" as the synergetic result of biodiversity and geodiversity.
This glossary of ecology is a list of definitions of terms and concepts in ecology and related fields. For more specific definitions from other glossaries related to ecology, see Glossary of biology, Glossary of evolutionary biology, and Glossary of environmental science.
Ecotopes are the smallest ecologically distinct landscape features in a landscape mapping and classification system. As such, they represent relatively homogeneous, spatially explicit landscape functional units that are useful for stratifying landscapes into ecologically distinct features for the measurement and mapping of landscape structure, function and change.
Ecosystem ecology is the integrated study of living (biotic) and non-living (abiotic) components of ecosystems and their interactions within an ecosystem framework. This science examines how ecosystems work and relates this to their components such as chemicals, bedrock, soil, plants, and animals.
Ecohydrology is an interdisciplinary scientific field studying the interactions between water and ecological systems. It is considered a sub discipline of hydrology, with an ecological focus. These interactions may take place within water bodies, such as rivers and lakes, or on land, in forests, deserts, and other terrestrial ecosystems. Areas of research in ecohydrology include transpiration and plant water use, adaption of organisms to their water environment, influence of vegetation and benthic plants on stream flow and function, and feedbacks between ecological processes, the soil carbon sponge and the hydrological cycle.
Biogeomorphology and ecogeomorphology are the study of interactions between organisms and the development of landforms, and are thus fields of study within geomorphology and ichnology. Organisms affect geomorphic processes in a variety of ways. For example, trees can reduce landslide potential where their roots penetrate to underlying rock, plants and their litter inhibit soil erosion, biochemicals produced by plants accelerate the chemical weathering of bedrock and regolith, and marine animals cause the bioerosion of coral. The study of the interactions between marine biota and coastal landform processes is called coastal biogeomorphology.
The following outline is provided as an overview of and topical guide to ecology:
The physiotope is the total abiotic matrix of habitat present within any certain ecotope. It refers to the landform, the rocks and the soils, the climate and the hydrology, and the geologic processes which marshalled all these resources together in a certain way and in this time and place
Pedotope is the total soil component of the abiotic matrix present in an ecotope. The pedotope is not one particular kind of soil, nor even the dominant kind of soil available in a location, but rather the total soil component available in the location.
Canada has 20 major ecosystems—ecozones, comprising 15 terrestrial units and 5 marine units. These ecozones are further subdivided into 53 ecoprovinces, 194 ecoregions, and 1,027 ecodistricts. These form the country's ecological land classification within the Ecological Land Classification framework adopted in 2017. They represent areas of the Earth's surface representative of large and very generalized ecological units characterized by interactive and adjusting biotic and abiotic factors.
Biogeoclimatic ecosystem classification (BEC) is an ecological classification framework used in British Columbia to define, describe, and map ecosystem-based units at various scales, from broad, ecologically-based climatic regions down to local ecosystems or sites. BEC is termed an ecosystem classification as the approach integrates site, soil, and vegetation characteristics to develop and characterize all units. BEC has a strong application focus and guides to classification and management of forests, grasslands and wetlands are available for much of the province to aid in identification of the ecosystem units.